x+12=21+54
45/21+21/45+12/54+54/12= ...................
tính giúp mk nha
sao bạn ko làm mà còn bảo mk làm mk đã hỏi thì phải trả lời ra kết quả chứ
45/21+21/45+12/54+54/12=
rut gon =5/3+3/5+2/9+9/2
quy dong =(5/3+3/5)+(2/9+9/2)
=15/15+18/18=1+1=2
luu y :neu tu va mau = nhau thi phan so do =1
chuc em hok tot
a)TÍNH BẰNG CÁCH THUẬN TIỆN
123 x 54 + 27 x 123 - 12 x 123 + 123 x 31
b)TÌM n
121/27 x 54/11 < n < 100/21 : 25/126
\(a,123\times54+27\times123-12\times123+123\times31\)
\(=123\times\left(54+27-12+31\right)\)
\(=123\times100\)
\(=12300\)
\(b,\dfrac{121}{27}\times\dfrac{54}{11}< n< \dfrac{100}{21}:\dfrac{25}{126}\)
\(22< n< \dfrac{100}{21}\times\dfrac{126}{25}\)
\(22< n< 24\)
Vì \(23>22\) và \(23< 24\) nên \(n=23\)
a)TÍNH BẰNG CÁCH THUẬN TIỆN
123 x 54 + 27 x 123 - 12 x 123 + 123 x 31
b)TÌM n
121/27 x 54/11 < n < 100/21 : 25/126
a123x54+27x123-12x123+123x31
=123:54+27:123-12:123+123:31
=6642+27:123-12:123+123:31
=6642+3321-12:123+123:31
=6642+3321-1476+123:31
=6642+3321-1476+3813
=12300
b,121/27x54/11<n>100/21:25/126
=22<n>24
n=23
d) 12 x 156 - 12 x 55 - 12
e) 12 x 11 + 21 x 11 + 11 x 33
g) 132 x 11 - 11 x 32 - 54 x 11
d) 12x 156 - 12 x 55 - 12
= 12 x ( 156 - 55 - 12 )
= 12 x 100
= 1200
e ) 12 x 11 + 21 x 11 + 11 x 33
= ( 12+ 21 + 33) x 12
= 66 x 11
= 726
g) 132 x 11 - 11 x 32 - 54 x 11
= ( 132 - 32 - 54 ) x 11
= 46 x 11
= 506
d) 12 x 156 - 12 x 55 - 12 = 12x(156 - 55 - 1 ) = 12 x 100 = 1200
e) 12 x 11 + 21 x 11 + 11 x 33 = 11 x ( 12 + 21 + 33 ) = 11 x 66 = 726
g) 132 x 11 - 11 x 32 - 54 x 11 = 11 x ( 132 - 32 - 54 ) = 11 x 46 = 506
d) \(12\times156-12\times55-12\) \(=12\times\left(156-55-1\right)\)
\(=12\times100=1200\)
e) \(12\times11+21\times11+11\times33\)\(=11\times\left(12+21+33\right)=11\times66=726\)
g) \(132\times11-11\times32-54\times11\) \(=11\times\left(132-32-54\right)=11\times46=506\)
Tìm x
11/8 : x - 2/5 + -1/6= -1/5
4/7. x-x. 1/3 + -16/21 = -2/3
-11/12.x + 15/2. ( x + -1/5) = 67/8
\(\dfrac{11}{8}:x-\dfrac{2}{5}+-\dfrac{1}{6}=-\dfrac{1}{5}\\ =>\dfrac{11}{8}:x-\dfrac{2}{5}=-\dfrac{1}{5}-\left(-\dfrac{1}{6}\right)\\ =>\dfrac{11}{8}:x-\dfrac{2}{5}=-\dfrac{1}{5}+\dfrac{1}{6}\\ =>\dfrac{11}{8}:x-\dfrac{2}{5}=-\dfrac{6}{30}+\dfrac{5}{30}\\ =>\dfrac{11}{8}:x-\dfrac{2}{5}=-\dfrac{1}{30}\\ =>\dfrac{11}{8}:x=-\dfrac{1}{30}+\dfrac{2}{5}\\ =>\dfrac{11}{8}:x=-\dfrac{1}{30}+\dfrac{12}{30}\\ =>\dfrac{11}{8}:x=\dfrac{11}{30}\\ =>x=\dfrac{11}{8}:\dfrac{11}{30}\\ =>x=\dfrac{11}{8}.\dfrac{30}{11}\\ =>x=\dfrac{30}{8}\\ =>x=\dfrac{15}{4}\\ \dfrac{4}{7}x-\dfrac{1}{3}x+\left(-\dfrac{16}{21}\right)=-\dfrac{2}{3}\\ =>\left(\dfrac{4}{7}-\dfrac{1}{3}\right)x=-\dfrac{2}{3}-\left(-\dfrac{16}{21}\right)\\ =>\left(\dfrac{12}{21}-\dfrac{7}{21}\right)x=-\dfrac{2}{3}+\dfrac{16}{21}\\ =>\dfrac{5}{21}x=-\dfrac{14}{21}+\dfrac{16}{21}\\ =>\dfrac{5}{21}x=\dfrac{2}{21}\\ =>x=\dfrac{2}{21}:\dfrac{5}{21}\)
\(=>x=\dfrac{2}{21}.\dfrac{21}{5}\\ =>x=\dfrac{2}{5}\\ -\dfrac{11}{12}x+\dfrac{15}{2}\left(x+-\dfrac{1}{5}\right)=\dfrac{67}{8}\\ =>-\dfrac{11}{12}x+\dfrac{15}{2}.x-\dfrac{1}{5}=\dfrac{67}{8}\\ =>\left(-\dfrac{11}{12}+\dfrac{15}{2}\right)x=\dfrac{67}{8}+\dfrac{1}{5}\\ =>\left(-\dfrac{11}{12}+\dfrac{90}{12}\right)x=\dfrac{335}{40}+\dfrac{8}{40}\\ =>\dfrac{79}{12}x=\dfrac{343}{40}\\ =>x=\dfrac{343}{40}:\dfrac{79}{12}\\ =>x=\dfrac{343}{40}.\dfrac{12}{79}\\ =>x=\dfrac{343.12}{40.79}\\ =>x=\dfrac{343.3}{10.79}\\ =>x=\dfrac{1029}{790}\)
Bài 2:
a) 37 x 7 - 17 x 11 + 13 x 37 + 17 x 21
b) 55 x 52 : 54 - 28 : 24
c) 311 x 12 + 312 x 5 - 314
`#040911`
`a)`
\(37 \times 7 - 17 \times 11 + 13 \times 37 + 17 \times 21\)
`= 37 \times (7 + 13) + 17 \times (21 - 11)`
`= 37 \times 20 + 17 \times 10`
`= 10 \times (37 \times 2 + 17)`
`= 10 \times 91`
`= 910`
`b)`
\(5^5 \times 5^2 \div 5^4 - 2^8 \div 2^4\)
`=`\(5^{5+2-4}-2^{8-4}\)
`= 5^3 - 2^4`
`= 125 - 16`
`= 109`
`c)`
\(3^{11}\times12+3^{12}\times5-3^{14}\)
`=`\(3^{11}\times\left(12+3\times5-3^3\right)\)
`=`\(3^{11}\times\left(12+15-27\right)\)
`=`\(3^{11}\times0=0\)
a) = 259 - 187 + 481 + 357
= 910
b) = 57 : 54 - 24
= 53 - 24
= 125 - 16
= 109
Bài 2:
a, 37 x 7 - 17 x 11 + 13 x 37 + 17 x 21
= ( 37 x 7 + 13 x 37) + ( 17 x 21 - 17 x 11)
= 37 x ( 7 + 13) + 17 x ( 21 - 11)
= 37 x 20 + 17 x 10
= 740 + 170
= 910
b, 55 x 52 : 54 - 28 : 24
= 57: 54 - 24
= 53 - 16
= 125 - 16
= 109
c, 311 x 12 + 312 x 5 - 314
311 x ( 12 + 3 x 5 - 133)
= 311 x ( 12 + 15 - 33)
= 311 x ( 27 - 27)
= 311 x 0
= 0
1. Tìm x thuộc Z, biết:
a, x + 26 = 39 + (-5)
b, |x| + 50= (-|-26|) +76
c, |x| + 17= (-21)+19
d. |x-21|= 2.(|-11| + |-3|)
e. |x-54|-7|=(-42) +12
a, x + 26 = 39 + (-5)
x + 26 = 39 - 5
x + 26 = 34
x = 34 - 26
x = 8
b, |x| + 50 = (-|-26|) +76
|x| +50 = (-26) +76
|x| +50 = 76 - 26
|x| +50 = 50
|x| = 50 -50
|x| = 0
c, |x| + 17 = (-21)+19
|x| + 17 = - (21-19)
|x| + 17 = - 2
|x| không tồn tại
d. |x-21|= 2.(|-11| + |-3|)
|x-21|= 2.(11+3)
|x-21|= 2.14
|x-21|= 28
x = 28+21 hoặc 21-28
x = 49 hoặc -7
e. hình như lộn đề vì |x-54|-7|
54^4 và 21^12
ntan ngu chưa từng thấy, ko biết lm thì đừng có nói bừa
544 và 2112
Ta có
2112=(213)4
2112=92614
<=> 544 < 92614
=> 544 < 2112
Chúc em học tốt.
4)tìm x:
a) 25 - ( 25 - x ) = 12 + ( 42 - 65 )
b) 215 + (-38) - 54 + 90 - ( -48 + x )=0
c) 15 - ( 15 + x ) = 21
d) 39 + ( x - 39 ) = 50
e) 13 - ( 25 - x)=7
g) x - 15 = -21
i) 12 - (30-x)= -23
k) 31 - ( 17+x) = 18
m) |x| - 5 = 12
a) \(25-\left(25-x\right)=12+\left(42-65\right)\)
\(25-\left(25-x\right)=12+\left(-23\right)\)
\(25-\left(25-x\right)=-11\)
\(25-x=25-\left(-11\right)\)
\(25-x=36\)
\(x=25-36\)
\(x=-11\)
Làm 2 câu dài cho bạn nhá! Mấy câu ngắn tương tự!
a, \(25-\left(25-x\right)=12+\left(42-65\right)\)
\(\Rightarrow25-25+x=12+42-65\)
\(\Rightarrow x=-11\)
b, \(215+\left(-38\right)-54+90-\left(-48+x\right)=0\)
\(\Rightarrow215-38-54+90+48-x=0\)
\(\Rightarrow x=261\)
m, \(\left|x\right|-5=12\)
\(\Rightarrow\left|x\right|=17\Rightarrow\left\{{}\begin{matrix}x=-17\\x=17\end{matrix}\right.\)
Chúc bạn học tốt!!!
so sánh : 54^4 và 21^12